U.S. Pat. No. 4,527,593, as well as co-pending U.S. Ser. No. 07/554,293, now allowed as U.S. Pat. No. 5,048,557, are hereby incorporated by reference into this disclosure.
The present invention relates generally to a field repairable apparatus, including a main valve and main valve seat, for use in filling containers to a predetermined level.
One of the applications for the inventions disclosed in U.S. Pat. No. 4,527,593 and co-pending Ser. No. 07/554,293 has been for use as a battery refill valve. Accordingly, one of the purposes of those inventions, as used with that particular application, is to reduce battery maintenance costs through the automatic filling of batteries connected thereto with liquid to predetermined levels. However, some maintenance is still required. Occasionally, for example, a battery-mounted watering system may experience damage during battery handling operations. Damage may also be caused to the working components by contamination entering the valves from the refill water supply, or from debris on the top of the battery entering through the quick disconnect fitting.
Periodic inspection of each cell is desire able to identify a faulty refill valve before it causes cell damage. Presently, this requires replacement of the entire valve, since the valve is permanently assembled. Such prior art valves employ a strong welded joint between the cap and body to accommodate the operating pressure and to maintain a precise fit between parts so that the valve performs properly and closes with a drip-tight seal over a long operating life, and under widely varying conditions of chemical and temperature exposure. A shift of just a few thousandths of an inch between critical parts, for example, can cause this prior art valve to malfunction.
Co-pending Ser. No. 07/554,293 discloses design improvements which simplify assembly procedures and improve valve reliability. These improvements have significantly increased valve service life by enabling the valve to resist the build-up of internal deposits, one of the more common causes of early valve failure. These design changes, however, still require a precise alignment of parts and a strong weld to retain the cap and body. Additionally, the maintenance cost of replacing a faulty valve remains the same, since the entire cap and body must be replaced as a unit.
The most significant maintenance costs presently occurring with valves of the type discussed above are due to valve damage repair as a consequence of battery handling. This damage generally affects only the exterior parts of the valve, and is likely to occur either to the cap assembly, or to the body assembly, but rarely to both at the same time. For example, the valve design disclosed in U.S. Pat. No. 4,527,593 has the advantage that the critical valve components are mounted in a body assembly below the battery cover plate, and thereby protected from handling damage. Thus, the components exposed to possible handling damage reside in the cap assembly, and are not affected by the factors which could damage critical valve components. In virtually any failure mode that can occur with such valve and cap assemblies, only one part of the refill valve, either the valve assembly or the cap assembly, need be replaced at a time. The natural repair interface is therefore at the cap/body joint.
Leakage has been the most significant cause for rejection during the manufacturing process. The occurrence of leakage is high because the valve housing, valve seat, and cap of the inventions referred to above are independent parts which are pressed together. The valve housing and cap are then seam welded together by a hand-held iron. The chance for misaligned parts is high.
However, as can be understood from the foregoing, refill valve assemblies not designed in accordance with the general design disclosed in U.S. Pat. No. 4,527,593, and having the valve components located above the battery cover, are exposed to handling damage as well as contamination factors. For this reason, even minor damage to these valves requires complete valve replacement.
Maintenance costs would therefore be minimized if the body, which contains all of the critical valve components, could be preserved if the cap were damaged. Conversely, if only the body were damaged, the cap and swivel connector could be preserved. However, in order to achieve a maintenance cost reduction, the replacement procedure would have to be able to be quickly, reliably and manually performed by unskilled workers, without the use of special tools. These workers would have to able to determine the problem readily and replace the damaged part.
Field personnel would be readily able to diagnose the faulty component with such an apparatus. For example, if a battery cell were over-filled or under-filled, then it would quickly be realized that the valve components are damaged. If there were visible damage to the cap assembly, or obvious leakage on the top of a battery, then the cap components would have to be replaced.